What can I do to get hair to grow where the FUEs were taken from?

You seem to have developed donor site depletion. This could be from over-harvesting during your FUE (taking too many grafts too close to each other). This can be shock loss of the donor area from over-harvesting.  If it is, it might recover. You will not know for at least six months from the date of the surgery. If it does not go away, then Scalp MicroPigmentation is the best solution.  See here:  https://scalpmicropigmentation.com/scar-covering/